Do all E9x M3s sound like they have an exhaust leak? Not like a 70 Mustang with a rusted exhaust, but more of a chuffing sound like the pipes aren't completely sealed? It's really noticeable when driving past raised barriers or in a tunnel.

Are you running stock exhausts? If so, they do tend to have a bit of a "chuffing" or "whispy" / "airy" sound, due to their mechanical sound absorption manuf'g characteristics. A 'free flow' sound absorption system, such as on most of the performance exhausts offered, will tend to run a more realistic sound, w/out that "chuffing". I like the REMUS' I've run on all my Bimmers. Not too loud, but deep, and only loud when I throttle it hard. On the newest M3's (I only wish I could afford :-) they have two versions I believe. A Sport version and a Race version. If you are running an aftermarket system, some use that O.E.M. style baffled / chambered style of sound absorption, and may "chuff" a bit as well.

No problem. I've been doing some research on performance exhausts lately, just thought I'd share a little of what I've learned... I was all set to get my used E 92 M3 from a dealer near here, got all psyched about it, and something came up with my other car, my E 36 M3, (a little spendy...) now I'm not able to pull it off... For a while at least. Had my REMUS "U.S. Sound / Race" exhaust on hold and everything... Ouch. Called 'em up, they were cool about it.

They all do that. It's because of the thin headers. Or simply headers. Most other cars have a big a$$ exhaust manifold that's way quieter than headers. If it was a leak it'd make a loud racket. This particular noise is pretty obvious when just starting the engine, and when putting a load on the engine and driving by a wall, barrier, etc. Sounds cool, actually .

Are you running stock exhausts? If so, they do tend to have a bit of a "chuffing" or "whispy" / "airy" sound, due to their mechanical sound absorption manuf'g characteristics. A 'free flow' sound absorption system, such as on most of the performance exhausts offered, will tend to run a more realistic sound, w/out that "chuffing". I like the REMUS' I've run on all my Bimmers. Not too loud, but deep, and only loud when I throttle it hard. On the newest M3's (I only wish I could afford :-) they have two versions I believe. A Sport version and a Race version. If you are running an aftermarket system, some use that O.E.M. style baffled / chambered style of sound absorption, and may "chuff" a bit as well.